[0001] The present invention relates to a multi-room heat pump type of air conditioning
apparatus wherein a single heat source device is connected to a plurality of indoor
units. More particularly, the present invention relates to an air conditioning apparatus
wherein cooling and heating can be selectively carried out for each indoor unit, or
wherein cooling can be carried out in one or some indoor units, and simultaneously
heating can be carried out in the other indoor unit(s).
[0002] Now, a prior art reference will be explained. Referring now to Figure 10, there is
shown a schematic diagram of the entire structure of a conventional air conditioning
apparatus disclosed in EP-A-0 453 271, which is depicted on the basis of the refrigerant
system of the apparatus. A similar apparatus is disclosed in EP-A-0 421 459.
[0003] Referring to Figures 11-13, there are shown the operation states in cooling or heating
in the conventional device shown in Figure 10.
[0004] Figure 11 is a schematic diagram showing the operation states of the conventional
device wherein solo cooling or solo heating is performed; Figures 12 and 13 are schematic
diagrams showing the operation states of cooling and heating concurrent operation;
Figure 12 is a schematic diagram showing the operation state of the conventional device
wherein heating is principally performed under cooling and heating concurrent operation
(total heating load is greater than total cooling load); and Figure 13 is a schematic
diagram showing the operation state of the conventional device wherein cooling is
principally performed under cooling and heating concurrent operation (total cooling
load is greater than total heating load).
[0005] Explanation of the prior art will be made for the case wherein a single heat source
device is connected to three or two indoor units. The following explanation is also
applicable to the case wherein a single source device is connected to more than three
indoor units.
[0006] In Figure 10, reference numeral A designates a heat source device. Reference numerals
B, C and D designate the indoor units which are connected in parallel as described
later on, and which have the same structure. Reference numeral E designates a junction
device which includes a first branch joint, a second flow controller, a second branch
joint, a gas-liquid separator, and first and second heat exchanging portions. Reference
numeral 1 designates a compressor. Reference numeral 2 designates a four port reversing
valve which can switch the flow direction of a refrigerant in the heat source device.
Reference numeral 3 designates an outdoor heat exchanger which is installed on the
side of the heat source device. Reference numeral 4 designates an accumulator which
is connected to the compressor 1, the reversing valve 2 and the outdoor heat exchanger
3 to constitute the heat source device A. Reference numeral 5 designates three indoor
heat exchangers in the indoor units B, C and D. Reference numeral 6 designates a first
main pipe which has a large diameter and which connects the four way reversing valve
2 and the junction device E. Reference numerals 6b, 6c and 6d designate first branch
pipes which connect the junction device E and the indoor heat exchangers 5 of the
respective indoor units B, C and D, and which correspond to the first main pipe 6.
Reference numeral 7 designates a second main pipe which has a smaller diameter than
the first main pipe 6, and which connects the junction device E and the outdoor heat
exchanger 3 of the heat source device A. Reference numerals 7b, 7c and 7d designate
second branch pipes which connect the junction device E and the indoor heat exchangers
5 of the respective indoor units B, C and D, and which correspond to the second main
pipe 7.
Reference numeral 8 designates three way switching valves which can selectively connect
the first branch pipes 6b, 6c and 6d to either the first main pipe 6 or the second
main pipe 7. Reference numeral 9 designates first flow controllers which are connected
to the respective indoor heat exchangers 5 in close proximity to the same, which are
controlled based on degree of superheat in cooling and degree of subcooling in heating
at refrigerant outlet sides of the respective indoor heat exchangers, and which are
connected to the second branch pipes 7b, 7c and 7d, respectively. Reference numeral
10 designates the first branch joint which includes the three way switching valves
8 which can selectively the first branch pipes 6b, 6c and 6d to either the first main
pipe 6 or the second main pipe 7. Reference numeral 11 designates the second branch
joint which includes the second branch pipes 7b, 7c and 7d, and a confluent portion
thereof. Reference numeral 12 designates the gas-liquid separator which is arranged
in the second main-pipe 7, and which has a gaseous phase zone connected to first ports
8a of the respective switching valves 8 and a liquid phase zone connected to the second
branch joint 11. Reference numeral 13 designates the second flow controller which
is connected between the gas-liquid separator 12 and the second branch joint 11, and
which can be selectively opened and closed. Reference numeral 14 designates a bypass
pipe which connects the second branch joint 11 to the first main pipe 6. Reference
numeral 15 designates a third flow controller which is arranged in the bypass pipe
14. Reference numerals 16b, 16c and 16d designate third heat exchanging portions which
are arranged in the bypass pipe 14 downstream of the third flow controller 15, and
which carry out heat exchange with the respective second branch pipes 7b, 7c and 7d
in the second branch joint 11. Reference numeral 16a designates the second heat exchanging
portion which is arranged in the bypass pipe 14 downstream of the third flow controller
15 and the third heat exchanging portions 16b, 16c and 16d, and which carries out
heat exchanging with the confluent portion where the second branch pipes 7b, 7c and
7d join in the second branch joint. Reference numeral 19 designates the first heat
exchanging portion which is arranged in the bypass pipe 14 downstream of the third
flow controller 15 and the second heat exchanging portion 16a, and which carries out
heat exchanging with the pipe which connects between the gas-liquid separator 12 and
the second flow controller 13. Reference numeral 17 designates a fourth flow controller
which is arranged in a pipe between the second branch joint 11 and the first main
pipe 6, and which can be selectively opened and closed. Reference numeral 32 designates
a third check valve which is arranged between the outdoor heat exchanger 3 and the
second main pipe 7, and which allows the refrigerant only to flow from the outdoor
heat exchanger 3 to the second main pipe 7. Reference numeral 33 designates a fourth
check valve which is arranged between the four way reversing valve 2 of the heat source
device A and the first main pipe 6, and which allows the refrigerant only to flow
from the first main pipe 6 to the reversing valve 2. Reference numeral 34 designates
a fifth check valve which is arranged between the reversing valve 2 and the second
main pipe 7, and which allows the refrigerant only to flow from the reversing valve
2 to the second main pipe 7. Reference numeral 35 designates a sixth check valve which
is arranged between the outdoor heat exchanger 3 and the first main pipe 6, and which
allows the refrigerant only to flow from the first main pipe 6 to the outdoor heat
exchanger 3. The third to sixth check valves 32-35 constitute a switching valve arrangement
40.
[0007] Reference numeral 41 designates a liquid purging pipe which has one end connected
to the gas-liquid separator 12 and the other end connected to the first main pipe
6. Reference numeral 42 designates a fifth flow controller which is arranged in the
liquid purging pipe 41 between the gas liquid separator 12 and the first main pipe
6. Reference numeral 43 designates a fourth heat exchanging portion which is arranged
in the liquid purging pipe 41 downstream of the fifth flow controller 42, and which
carries out heat exchange with the pipe connecting between the gas-liquid separator
12 and the first branch joint 10.
[0008] Reference numeral 23 designates a first temperature detector which is attached to
the pipe connecting between the second flow controller 13 and the first heat exchanging
portion 19. Reference numeral 25 designates a first pressure detector which is attached
to the same pipe as the first temperature detector 23. Reference numeral 26 designates
a second pressure detector which is attached to the second branch joint 11. Reference
numeral 52 designates a third pressure detector which is attached to the pipe connecting
between the first main pipe 6 and the first branch joint 10. Reference numeral 51
designates a second temperature detector which is attached to the liquid purging pipe
41 at a refrigerant outlet of the fourth heat exchanging portion 43. Reference numeral
53 designates a third temperature detector which is attached to the bypass pipe 14
at a refrigerant outlet of the first heat exchanging portion 19.
[0009] The operation of the prior art as constructed above will be explained.
[0010] Firstly, the case wherein only room cooling is performed will be explained with reference
to Figure 11.
[0011] In this case, the flow of the refrigerant is indicated by arrows of solid line. The
refrigerant gas which has discharged from the compressor 1 and been a gas having high
temperature under high pressure passes through the four way reversing valve 2, and
is heat exchanged and condensed in the outdoor heat exchanger 3. Then, the refrigerant
passes through the third check valve 32, the second main pipe 7, the separator 12
and the second flow controller 13 in that order. The refrigerant further passes through
the second branch joint 11 and the second branch pipes 7b, 7c and 7d, and enters the
indoor units B, C and D. The refrigerant which has entered the indoor units B, C and
D is depressurized to low pressure by the first flow controllers 9 which are controlled
based on degree of superheat at the outlet refrigerants of the respective indoor heat
exchanger 5. In the indoor heat exchangers 5, the refrigerant thus depressurized carries
out heat exchanging with indoor air to be evaporated and gasified, thereby cooling
the rooms. The refrigerant so gasified passes through the first branch pipes 6b, 6c
and 6d, the three way switching valves 8, and the first branch joint 10. Then the
refrigerant is inspired into the compressor 1 through the first main pipe 6, the fourth
check valve 33, the four way reversing valve 2, and the accumulator 4. In this way,
a circulation cycle is formed to carry out cooling. At this mode, the three way switching
valves 8 have the first ports 8a closed, and second ports 8b and third ports 8c opened.
At the time, the first main pipe 6 is at low pressure in it, and the second main pipe
7 is at high pressure in it, which necessarily make the third check valve 32 and the
fourth check valve 33 to conduct for the refrigerant. In addition, in this mode, the
refrigerant, which has passed through the second flow controller 13, partly enters
the bypass pipe 14 where the entered part of the refrigerant is depressurized to low
pressure by the third flow controller 15. The refrigerant thus depressurized carries
out heat exchanging with the second branch pipes 7b, 7c and 7d at the third heat exchanging
portions 16b 16c and 16d of the indoor units, with the confluent portion of the second
branch pipes 7b, 7c and 7d at the second heat exchanging portion 16a in the second
branch joint 11, and at the first heat exchanging portion 19 with the refrigerant
which enters the second flow controller 13. The refrigerant is evaporated due to such
heat exchanging, and enters the first main pipe 6. Then the refrigerant is inspired
into the compressor 1 through the fourth check valve 33, the first four way reversing
valve 2 and the accumulator 4. On the other hand, the refrigerant, which has heat
exchanged at the first heat exchanging portion 19, at the second heat exchanging portion
16a and at the third heat exchanging portions 16b, 16c and 16d, and has been cooled
so as to get sufficient degree of subcooling, enters the indoor units B, C and D which
are expected to carry out room cooling.
[0012] When the amount of the refrigerant which is sealed in the air conditioning apparatus
is not enough to fill the second main pipe in cooling with a liquid refrigerant having
high pressure, the refrigerant which has been condensed in the outdoor heat exchanger
3 and has a two phase state under high pressure passes through the second main pipe
7 and the gas-liquid separator 12. Then the two phase refrigerant carries out heat
exchange, at the first heat exchanging portion 19, at the second heat exchanging portion
16a, and at the third heat exchanging portions 16b, 16c and 16d, with the refrigerant
which has been depressurized to low pressure by the third flow controller 15 and flows
through the bypass pipe. The refrigerant which has liquefied and cooled due to such
heat exchange to obtain sufficient degree of subcooling, and flows into the indoor
units B, C and D which are expected to carry out cooling.
[0013] Secondly, the case wherein only heating is performed will be described with reference
Figure 11. In this case, the flow of the refrigerant is indicated by arrows of dotted
line. The refrigerant which has been discharged from the compressor 1 and been a gas
having high temperature under high pressure passes through the four way reversing
valve 2, the fifth check valve 34, the second main pipe 7, and the gas-liquid separator
12. Then the refrigerant passes through the first branch joint 10, the three way switching
valves 8, and the first branch pipes 6b, 6c and 6d. After that, the refrigerant enters
the respective indoor units B, C and D where the refrigerant carries out heat exchanging
with indoor air. The refrigerant is condensed to be liquefied due to such heat exchanging,
thereby heating the rooms. The refrigerant thus liquefied passes through the first
flow controllers 9 which are controlled based on degree of subcooling at the refrigerant
outlets of the respective indoor heat exchangers 5. Then the refrigerant enters the
second branch joint 11 through the second branch pipes 7b, 7c and 7d, and joins there.
Then the joined refrigerant passes through the fourth flow controller 17. The refrigerant
is depressurized by either the first flow controllers 9 or the fourth flow controller
17 to take a two phase state having low pressure. The refrigerant thus depressurized
enters the outdoor heat exchanger 3 through the first main pipe 6 and the sixth check
valve 35 of the heat source device A, and carries out heat exchanging to be evaporated
and gasified. The refrigerant thus gasified is inspired into the compressor 1 through
the four way reversing valve 2, and the accumulator 4. In this way, a circulation
cycle is formed to carry out room heating. In this mode, the switching valves 8 have
the second ports 8b closed, and the first and the third ports 8a and 8c opened.
[0014] In this mode, the first main pipe 6 is at low pressure in it, and the second main
pipe 7 is at high pressure in it, which necessarily causes the fifth check valve 34
and the sixth check valve 35 to conduct for the refrigerant.
[0015] Thirdly, the case wherein heating is principally performed in cooling and heating
concurrent operation will be explained with reference to Figure 12. Explanation will
be made for the case wherein the indoor units B and C are expected to carry out heating,
and the indoor unit D is expecting to carry out cooling. In Figure 12, arrows of dotted
line indicate the flow of the refrigerant.
[0016] The refrigerant which has been discharged from the compressor 1, and been a gas having
high temperature under high pressure passes through the four way reversing valve 2,
and then reaches the junction device E through the fifth check valve 34 and the second
main pipe 7. The refrigerant flows through the gas-liquid separator 12. In addition,
the refrigerant passes through the first branch joint 10, the three way switching
valves 8 connected to the indoor units B and C, and the first branch pipes 6b and
6c in that order, and enters the indoor units B and C which are expected to carry
out heating. In the indoor heat exchangers 5 of the respective indoor units B and
C, the refrigerant carries out heat exchange with indoor air to be condensed and liquefied,
thereby heating the rooms. The refrigerant thus liquefied passes through the first
flow controllers 9 of the indoor units B and C, the first controllers 9 of the indoor
units B and C being almost fully opened under the control based on degree of subcooling
at the refrigerant outlets of the corresponding indoor heat exchangers 5. The refrigerant
is slightly depressurized by these first flow controllers 9 to have a pressure (medium
pressure) between the high pressure and the low pressure, and flows into the second
branch joint 11 through the second branch pipes 7b and 7c. After that, a part of the
refrigerant passes through the second branch pipe 7d of the indoor unit D which is
expected to carry out cooling, and enters the indoor unit D. The refrigerant flows
into the first flow controller 9 of the indoor unit D, the first flow controller 9
being controlled based on degree of superheat at the refrigerant outlet of the corresponding
indoor heat exchanger 5. After the refrigerant is depressurized by this first flow
controller 9, it enters the indoor heat exchanger 5, and carries out heat exchange
to be evaporated and gasified, thereby cooling the room. Then the refrigerant enters
the first main pipe 6 through the three way switching valve 8 which is connected to
the indoor unit D.
[0017] On the other hand, another part of refrigerant passes through the fourth flow controller
17 which is selectively opened and closed, and which is controlled in such a way to
make constant the difference between the high pressure in the second main pipe 7 and
the medium pressure in the second branch joint 11. Then the refrigerant joins with
the refrigerant which has passed the indoor unit D which is expected to carry out
cooling. After that, the refrigerant thus joined passes through the first main pipe
6 having such a larger diameter, and the sixth check valve 35, and enters the outdoor
exchanger 3 where the refrigerant carries out heat exchange to be evaporated and gasified.
The refrigerant thus gasified is inspired into the compressor 1 through the reversing
valve 2 and the accumulator 4. In this way, a circulation cycle is formed to carry
out the cooling and heating concurrent operation wherein heating is principally performed.
At this time, the difference between the evaporation pressure in the indoor heat exchanger
5 of the cooling indoor unit D and that of the outdoor heat exchanger 3 lessens because
of switching to the first main pipe 6 having such a greater diameter. At that time,
the three port switching valves 8 which are connected to the heating indoor units
B and C have the second ports 8b closed, and the first and third ports 8a and 8c opened.
The three port switching valve 8 which is connected to the cooling indoor unit D has
the second port 8a closed, and the first port 8b and the third port 8c opened.
[0018] In this mode, the first main pipe 6 is at low pressure in it, and the second main
pipe 7 is at high pressure in it, which necessarily causes the fifth check valve 34
and the sixth check valve 35 to conduct for the refrigerant. At this circulation cycle,
the remaining part of the liquefied refrigerant goes into the bypass pipe 14 from
the confluent portion where the second branch pipes 7b, 7c and 7d join together. The
refrigerant which has gone into the bypass pipe 14 is depressurized to low pressure
by the third flow controller 15. The refrigerant thus depressurized carries out heat
exchange with the refrigerant in the confluent portion of the second branch pipes
7b, 7c and 7d in the second branch joint 11 at the second heat exchanging portion
16a, and at the first heat exchanging portion 19 with the refrigerant which flows
into the second flow controller 13. The refrigerant is evaporated by such heat exchange,
and enters the first main pipe 6. After that, the refrigerant flows into the sixth
check valve 35 and then into the outdoor heat exchanger 3 where it performs heat exchange
to be evaporated and gasified. The refrigerant is inspired into the compressor 1 through
the four way reversing valve 2 and the accumulator 4. On the other hand, the refrigerant
in the second branch joint 11 which has carried out heat exchange and cooled at the
first heat exchanging portion 19, at the second heat exchanging portion 16a, and at
the third heat exchanging portions 16b, 16c and 16d to obtain sufficient degree of
subcooling flows into the indoor unit D which is expected to cool the room.
[0019] Fourthly, the case wherein cooling is principally performed in cooling and heating
concurrent operation will be described with reference to Figure 13.
[0020] Explanation will be made for the case wherein the indoor units B and C are expected
to carry out cooling, and the indoor unit D is expected to carry out heating.
[0021] In Figure 13, arrows of solid lines indicate the flow of the refrigerant. The refrigerant
which has been discharged from the compressor 1 and been a gas having high temperature
under high pressure carries out heat exchange at an arbitrary amount in the outdoor
heat exchanger 3 to take a two phase state having high temperature under high pressure.
Then the refrigerant passes through the third check valve 32 and the second main pipe
7, and is forwarded to the gas-liquid separator 12 in the junction device E. The refrigerant
is separated into a gaseous refrigerant and a liquid refrigerant there, and the gaseous
refrigerant thus separated flows through the first branch joint 10, and the three
way switching valve 8 and the first branch pipe 6d which are connected to the indoor
unit D, in that order, the indoor unit D being expected to heat the room. The refrigerant
flows into the indoor unit D, and carries out heat exchange with indoor air to be
condensed and liquefied, thereby heating the room. In addition, the refrigerant passes
through the first flow controller 9 connected to the heating indoor unit D, this first
flow controller 9 being almost fully opened under control based on degree of subcooling
at the refrigerant outlet of the indoor heat exchanger 5 of the heating indoor unit
D. The refrigerant is slightly depressurized by this first flow controller 9 to have
a pressure (medium pressure) between the high pressure and the low pressure, and flows
into the second branch joint 11. On the other hand, the remaining liquid refrigerant
enters the second branch joint 11 through the second flow controller 13 which is controlled
in such a way to make constant the difference between the high pressure and the medium
pressure. Then the refrigerant joins there with the refrigerant which has passed through
the heating indoor unit D. The refrigerant thus joined passes through the second branch
joint 11, and then the second branch pipes 7b and 7c, respectively, and enters the
respective indoor units B and C. The refrigerant which has flowed into the indoor
units B and C is depressurized to low pressure by the first flow controllers 9 of
the indoor units B and C, these first flow controllers 9 being controlled based on
degree of superheat at the refrigerant outlets of the corresponding indoor heat exchangers
5. Then the refrigerant flows into the indoor heat exchangers 5, and carries out heat
exchange with indoor air to be evaporated and gasified, thereby cooling these rooms.
In addition, the refrigerant thus gasified passes through the first branch pipes 6b
and 6c, the three way switching valves 8 connected to the indoor units B and C, and
the first branch joint 10. Then the refrigerant is inspired into compressor 1 through
the first main pipe 6, the fourth check valve 33, the four way reversing valve 2,
and the accumulator 4. In this way, a circulation cycle is formed to carry out the
cooling and heating concurrent operation wherein cooling is principally performed.
In this mode, the three way switching valves 8 which are connected to the indoor units
B and C have the first ports 8a closed, and the second and third ports 8b and 8c opened.
The three way switching valve 8 which is connected to the indoor unit D has the second
port 8b closed, and the first and third ports 8a and 8c opened.
[0022] At that time, the first main pipe 6 is at low pressure in it, and the second main
pipe 7 is a high pressure in it, which necessarily causes the third check valve 32
and the fourth check valve 33 to conduct for the refrigerant.
[0023] In this circulation cycle, the liquid refrigerant partly enters the bypass pipe 14
from the confluent portion where the second branch pipes 7b, 7c and 7d join together.
The liquid refrigerant which has entered into the bypass pipe 14 is depressurized
to low pressure by the third flow controller 15. The refrigerant thus depressurized
carries out heat exchange at the second heat exchanging portion 16a with the refrigerant
in the confluent portion of the second branch pipes 7b, 7c and 7d in the second branch
joint 11, and at the first heat exchanging portion 19 with the refrigerant which flows
into the second flow controller 13. The refrigerant is evaporated by such heat exchange,
and enters the first main pipe 6. The refrigerant which has entered the first main
pipe 6 is inspired into the compressor 1 through the fourth check valve 33, the four
way reversing valve 2, and the accumulator 4.
[0024] On the other hand, the refrigerant in the second branch joint 11 which has carried
out heat exchange and cooled at the first heat exchanging portion 19, at the second
heat exchanging portion 16a, and at the third heat exchanging portions 16b, 16c and
16d to obtain sufficient degree of subcooling flows into the indoor units B and C
which are expected to carry out room cooling.
[0025] When the liquid level at which the gaseous refrigerant and the liquid refrigerant
separated in the gas liquid separator 12 are divided is below the liquid purging pipe
41 of the gas-liquid separator 12, the gaseous refrigerant enters the liquid purging
pipe 41, and is depressurized to low pressure by the fifth flow controller 42. The
amount of the refrigerant which is flowing through the fifth flow controller 42 is
small because the refrigerant at the inlet of the fifth flow controller 42 is in the
form of gas. As a result, the refrigerant which is flowing through the liquid purging
pipe 41 carries out heat exchange, at the fourth heat exchanging portion 43, with
the gaseous refrigerant which goes from the gas-liquid separator 12 to the first branch
joint 10 and has high pressure. The refrigerant in the liquid purging pipe 41 becomes
a superheated gas having low pressure due to such heat exchange, and enters the first
main pipe 6.
[0026] Conversely, when the liquid level at which the gaseous refrigerant and the liquid
refrigerant separated in the gas-liquid separator 12 are divided is above the liquid
purging pipe 41 of the gas liquid separator 12, the liquid refrigerant enters the
liquid purging pipe 41, and is depressurized to low pressure by the fifth flow controller
42. Because the refrigerant at the inlet of the fifth flow controller 42 is in the
form of liquid, the amount of the refrigerant which is flowing through the fifth flow
controller 42 is greater in comparison with the case wherein the refrigerant at the
fifth flow controller 42 is in the form of gas. As a result, even when the refrigerant
which is flowing through the liquid purging pipe 41 carries out-heat exchanger, at
the fourth heat exchanging portion 43, with the gaseous refrigerant which goes from
the gas liquid separator 12 into the first branch joint 10 and has high pressure,
the refrigerant in the liquid purging pipe 41 enters the first main pipe 6 in the
form of two phase state without becoming a superheated gas having low pressure.
[0027] The conventional air conditioning apparatus involves the following problem:
[0028] The compressor could be seized by a lubricating oil which has been discharged with
the refrigerant from the compressor and stayed in the junction device.
[0029] It is an object of the present invention to provide an air conditioning apparatus
capable of returning to a compressor a lubricating oil (hereinbelow, referred to as
oil recovery) which has been discharged with a refrigerant from the compressor and
stayed in a junction device.
[0030] The present invention provides air conditioning apparatus as set forth in claims
1 to 3.
[0031] In drawings:
Figure 1 is a schematic diagram of the entire structure of a first embodiment of the
air conditioning apparatus according to the present invention, which is depicted on
the basis of the refrigerant system of the apparatus;
Figure 2 is a schematic diagram showing a refrigerant circuit to help explain the
operation states of the first embodiment of Figure 1 wherein solo cooling or solo
heating is performed;
Figure 3 is a schematic diagram showing a refrigerant circuit to help explain the
operation state of the first embodiment of Figure 1 wherein heating is principally
performed under cooling and heating concurrent operation;
Figure 4 is a schematic diagram showing a refrigerant circuit to help explain the
operation state of the first embodiment of the Figure 1 wherein cooling is principally
performed under cooling and heating concurrent operation;
Figure 5 is a block diagram showing oil recovery in the apparatus according to the
first embodiment;
Figure 6 is a flowchart showing the oil recovery;
Figure 7 is a graph showing a change in the valve setting of a second flow controller
for oil recovery in the first embodiment;
Figure 8 is a schematic diagram showing the entire structure of a second embodiment
which is depicted on the basis of the refrigerant system of the apparatus;
Figure 9 is a schematic diagram of the entire structure of a modification of the first
and second embodiments according to the present invention, which is depicted on the
basis of the refrigerant system of the apparatus;
Figure 10 is a schematic diagram of the entire structure of a conventional air conditioning
apparatus, which is depicted on the basis of the refrigerant system of the apparatus;
Figure 11 is a schematic diagram showing the operation states of the conventional
apparatus of Figure 10 wherein solo cooling or solo heating is performed;
Figure 12 is a schematic diagram showing the operation state of the conventional apparatus
of Figure 10 wherein heating is principally performed under cooling and heating concurrent
operation;
Figure 13 is a schematic diagram showing the operation state of the conventional apparatus
of the Figure 10 wherein cooling is principally performed under cooling and heating
concurrent operation.
[0032] Now, the present invention will be described in detail with reference to preferred
embodiments illustrated in the accompanying drawings.
EMBODIMENT 1:
[0033] A first embodiment of the present invention will be described.
[0034] Figure 1 is a schematic diagram of the entire structure of the first embodiment of
the air conditioning apparatus according to the present invention, which is depicted
on the basis of the refrigerant system of the apparatus. Figures 2 to 4 are schematic
diagrams showing the operation states in cooling or heating in the first embodiment
of Figure 1; Figure 2 being a schematic diagram showing the operation states wherein
solo cooling or solo heating is performed; and Figure 3 and 4 being schematic diagrams
showing the operation states in cooling and heating concurrent operation, Figure 3
being a schematic diagram showing the operation state wherein heating is principally
performed under cooling and heating concurrent operation, and Figure 4 being a schematic
diagram showing the operation state wherein cooling is principally performed under
cooling and heating concurrent operation.
[0035] Although explanation on the embodiment will be made in reference to the case wherein
a single outdoor unit as a heat source device is connected to three indoor units,
the explanation is also applicable to the case wherein the outdoor unit is connected
to two or more indoor units.
[0036] In Figure 1, reference A designates an outdoor unit as a heat source device. Reference
B, C and D designate indoor units which are connected in parallel as described later
and have the same structure as each other. Reference E designates a junction device
which includes a first branch joint 10, a second flow controller 13, a second branch
joint 11, a gas-liquid separator 12, heat exchanging portions 16a, 16b, 16c, 16d and
19, a third flow controller 15, and a fourth flow controller 17, as described later.
[0037] Reference numeral 1 designates a compressor. Reference numeral 2 designates a four
port reversing valve which can switch the flow direction of a refrigerant in the heat
source device. Reference numeral 3 designates an outdoor heat exchanger which is installed
on the side of the heat source device. Reference numeral 4 designates an accumulator
which is connected to the compressor 1 through the reversing valve 2. These members
constitute the heat source device A. Reference numeral 5 designates three indoor heat
exchangers in the indoor units B, C and D. Reference numeral 6 designates a first
main pipe which has a large diameter and which connects the four way reversing valve
2 of the heat source device A and the junction device E through a fourth check valve
33 as stated later. Reference numerals 6b, 6c and 6d designate first branch pipes
which connect the junction device E and the indoor heat exchangers 5 of the respective
indoor units B, C and D, and which correspond to the-first main pipe 6. Reference
numeral 7 designates a second main pipe which has a smaller diameter than the first
main pipe 6, and which connects the junction device E and the outdoor heat exchanger
3 of the heat source device A through a third check valve 32 as stated later. Reference
numerals 7b, 7c and 7d designate second branch pipes which connect the junction device
E and the indoor heat exchangers 5 of the respective indoor units B, C and D through
first flow controllers 9, and which correspond to the second main pipe 7. Reference
numeral 8 designates three way switching valves which can selectively connect the
first branch pipes 6b, 6c and 6d to either the first main pipe 6 or the second main
pipe 7. Reference numeral 9 designates the first flow controllers which are connected
to the respective indoor heat exchangers 5 in close proximity to the same, which are
controlled based on degree of superheat at refrigerant outlet sides of the respective
indoor heat exchangers in cooling and on degree of subcooling in heating, and which
are connected to the second branch pipes 7b, 7c and 7d, respectively. Reference numeral
10 designates the first branch joint which includes the three way switching valves
8 which can selectively the first branch pipes 6b, 6c and 6d to either the first main
pipe 6 or the second main pipe 7. Reference numeral 11 designates the second branch
joint which includes the second branch pipes 7b, 7c and 7d, and the second main pipe
7. Reference numeral 12 designates the gas-liquid separator which is arranged in the
second main pipe 7, and which has a gas phase zone connected to first ports 8a of
the respective switching valves 8 and a liquid phase zone connected to the second
branch joint 11. Reference numeral 13 designates the second flow controller which
is connected between the gas-liquid separator 12 and the second branch joint 11, and
which can be selectively opened and closed. Reference numeral 14 designates a bypass
pipe which connects the second branch joint 11 to the first main pipe 6. Reference
numeral 15 designates the third flow controller (shown as an electric expansion valve)
which is arranged in the bypass pipe 14. Reference numeral 16a designates the second
heat exchanging portion which is arranged in the bypass pipe 14 downstream of the
third flow controller 15, and which carries out heat exchanging with a confluent portion
where the second branch pipes 7b, 7c and 7d join in the second branch joint. Reference
numerals 16b, 16c and 16d designate the third heat exchanging portions which are arranged
in the bypass pipe 14 downstream of the third flow controller 15, and which carry
out heat exchange with the respective second branch pipes 7b, 7c and 7d in the second
branch joint 11. Reference numeral 19 designates the first heat exchanging portion
which is arranged in the bypass pipe 14 downstream of the third flow controller 15
and the second heat exchanging portion 16a, and which carries out heat exchanging
with a pipe which connects between the gas-liquid separator 12 and the second flow
controller 13. Reference numeral 17 designates the fourth flow controller (shown as
an electric expansion valve) which is arranged in a pipe between the second branch
joint 11 and the first main pipe 6, and which can be selectively opened and closed.
Reference numeral 32 designates the third check valve which is arranged between the
outdoor heat exchanger 3 and the second main pipe 7, and which allows a refrigerant
only to flow from the outdoor heat exchanger 3 to the second main pipe 7. Reference
numeral 33 designates the fourth check valve which is arranged between the four way
reversing valve 2 of the heat source device A and the first main pipe 6, and which
allows the refrigerant only to flow from the first main pipe 6 to the reversing valve
2. Reference numeral 34 designates a fifth check valve which is arranged between the
reversing valve 2 and the second main pipe 7, and which allows the refrigerant only
to flow from the reversing valve 2 to the second main pipe 7. Reference numeral 35
designates a sixth check valve which is arranged between the outdoor heat exchanger
3 and the first main pipe 6, and which allows the refrigerant only to flow from the
first main pipe 6 to the outdoor heat exchanger 3. These check valves 32-35 constitute
a switching valve arrangement 40.
[0038] Reference numeral 25 designates a first pressure detector which is arranged between
the first branch joint 10 and the second flow controller 13. Reference numeral 26
designates a second pressure detector which is arranged between the second flow controller
13 and the fourth flow controller 17.
[0039] Reference numeral 50 designates a low pressure saturation temperature detector which
is arranged in a pipe connecting between the reversing valve 2 and the accumulator
4. Reference numeral 18 designates a fourth pressure detector which is arranged in
a pipe connecting between the compressor 1 and the reversing valve 2.
[0040] The operation of the first embodiment as constructed above will be explained.
[0041] Firstly, the case wherein only cooling is performed will be explained with reference
to Figure 2.
[0042] In this case, the flow of the refrigerant is indicated by arrows of solid line. The
compressor 1 has capacity controlled so that a temperature detected by the low pressure
saturation temperature detector 50 achieves a predetermined value. The refrigerant
gas which has discharged from the compressor 1 and had high temperature under high
pressure passes through the four way reversing valve 2, and is heat exchanged and
condensed in the outdoor heat exchanger 3. Then, the refrigerant passes through the
third check valve 32, the second main pipe 7, the separator 12 and the second flow
controller 13 in that order. The refrigerant further passes through the second branch
joint 11 and the second branch pipes 7b, 7c and 7d, and enters the indoor units B,
C and D. The refrigerant which has entered the indoor units B, C and D is depressurized
to low pressure by the first flow controllers 9 which are controlled based on degree
of superheat at the outlets of the respective indoor heat exchanger 5. In the indoor
heat exchangers 5, the refrigerant thus depressurized carries out heat exchanging
with indoor air to be evaporated and gasified, thereby cooling the rooms. The refrigerant
so gasified passes through the first branch pipes 6b, 6c and 6d, the three way switching
valves 8, and the first branch joint 10. Then the refrigerant is inspired into the
compressor 1 through the first main pipe 6, the fourth check valve 33, the four way
reversing valve 2 in the heat source device A, and the accumulator 4. In this way,
a circulation cycle is formed to carry out room cooling. At this mode, the three way
switching valves 8 have the first ports 8a closed, and second ports 8b and third ports
8c opened. At the time, the first main pipe 6 is at low pressure in it, and the second
main pipe 7 is at high pressure in it, which necessarily make the third check valve
32 and the fourth check valve 33 to conduct for the refrigerant. In addition, in this
mode, the refrigerant, which has passed through the second flow controller 13, partly
enters the bypass pipe 14 where the entered part of the refrigerant is depressurized
to low pressure by the third flow controller 15. The refrigerant thus depressurized
carries out heat exchanging with the second branch pipes 7b, 7c and 7d at the third
heat exchanging portions 16b 16c and 16d, with the confluent portion of the second
branch pipes 7b, 7c and 7d at the second heat exchanging portion 16a in the second
branch joint 11, and at the first heat exchanging portion 19 with the refrigerant
which flows into the second flow controller 13. The refrigerant is evaporated due
to such heat exchanging, and enters the first main pipe 6 and the fourth check valve
33. Then the refrigerant is inspired into the compressor 1 through the first four
way reversing valve 2 and the accumulator 4.
[0043] On the other hand, the refrigerant, which has heat exchanged at the first heat exchanging
portion 19, the second heat exchanging portion 16a, and the third heat exchanging
portions 16b, 16c and 16d, and has been cooled so as to get sufficient subcooling,
enters the indoor units B, C and D which are expected to carry out cooling.
[0044] Secondly, the case wherein only heating is performed will be described with reference
Figure 2. In this case, the flow of the refrigerant is indicated by arrows of dotted
line. The compression 1 has capacity controlled so that a pressure detected by the
fourth pressure detector 18 achieves a predetermined value.
[0045] The refrigerant which has been discharged from the compressor 1 and been a gas having
high temperature under high pressure passes through the four way reversing valve 2,
the fifth check valve 34, the second main pipe 7, and the gas-liquid separator 12.
Then the refrigerant passes through the first branch joint 10, the three way switching
valves 8, and the first branch pipes 6b, 6c and 6d in that order. After that, the
refrigerant enters the respective indoor units B, C and D where the refrigerant carries
out heat exchanging with indoor air. The refrigerant is condensed to be liquefied
due to such heat exchanging, thereby heating the rooms. The refrigerant thus liquefied
passes through the first flow controllers 9 which are almost fully opened, being controlled
based on degree of subcooling at the refrigerant outlets of the respective indoor
heat exchangers 5. Then the refrigerant enters the second branch joint 11 through
the second branch pipes 7b, 7c and 7d, and joins there. Then the joined refrigerant
passes through the fourth flow controller 17. The refrigerant is depressurized by
either the first flow controllers 9 or the third and fourth flow controllers 15 and
17 to take a gas liquid two phase state having low pressure. The refrigerant thus
depressurized enters the outdoor heat exchanger 3 through the first main pipe 6 and
the sixth check valve 35 of the heat source device A, and carries out heat exchanging
to be evaporated and gasified. The refrigerant thus gasified is inspired into the
compressor 1 through the four way reversing valve 2 of the heat source device A, and
the accumulator 4. In this way, a circulation cycle is formed to carry out heating.
In this mode, the switching valves 8 have the second ports 8b closed, and the first
and the third ports 8a and 8c opened.
[0046] In this mode, the first main pipe 6 is at low pressure in it, and the second main
pipe 7 is at high pressure in it, which necessarily causes the fifth check valve 34
and the sixth check valve 35 to conduct for the refrigerant.
[0047] At that time, the second flow controller 13 is fully closed in a normal state.
[0048] Thirdly, the case wherein heating is principally performed in cooling and heating
concurrent operation will be explained with reference to Figure 3. In Figure 3, arrows
of dotted line indicate the flow of the refrigerant. The compression 1 has capacity
controlled so that a pressure detected by the fourth pressure detector 18 achieves
a predetermined value. The refrigerant which has been discharged from the compressor
1, and been a gas having high temperature under high pressure passes through the four
way reversing valve 2, and then reaches the junction device E through the fifth check
valve 34 and the second main pipe 7. The refrigerant flows through the gas-liquid
separator 12. In addition, the refrigerant passes through the first branch joint 10,
the three way switching valves 8, and the first branch pipes 6b and 6c in that order,
and enters the indoor units B and C which are expected to carry out heating. In the
indoor heat exchangers 5 of the respective indoor units B and C, the refrigerant carries
out heat exchange with indoor air to be condensed and liquefied, thereby heating the
rooms. The refrigerant thus condensed and liquefied passes through the first flow
controllers 9 of the indoor units B and C, the first controllers 9 of the indoor units
B and C being almost fully opened under control based on degree of subcooling at the
refrigerant outlets of the corresponding indoor heat exchangers 5. The refrigerant
is slightly depressurized by these first flow controllers 9, and flows into the second
blanch joint 11. After that, a part of the refrigerant passes through the second branch
pipe 7d of the indoor unit D which is expected to carry out cooling, and enters the
indoor unit D. The refrigerant flows into the first flow controller 9 of the indoor
unit D, the first flow controller 9 being controlled based on degree of superheat
at the refrigerant outlet of the corresponding indoor heat exchanger 5. After the
refrigerant is depressurized by this first flow controller 9, it enters the indoor
heat exchanger 5, and carries out heat exchange to be evaporated and gasified, thereby
cooling the room. Then the refrigerant enters the first main pipe 6 through the first
branch pipe 6d and the three way switching valve 8 which is connected to the indoor
unit D.
[0049] On the other hand, another part of refrigerant passes through the fourth flow controller
17 which is controlled so that a difference between a pressure detected by the first
pressure detector 25 and a pressure detected by the second pressure detector 26 falls
into a predetermined range. Then the refrigerant joins with the refrigerant which
has passed the indoor unit D which is expected to carry out cooling. After that, the
refrigerant thus joined passes through the first main pipe 6 having such a larger
diameter, and the sixth check valve 35 of the heat source device A, and enters the
outdoor exchanger 3 where the refrigerant carries out heat exchange to be evaporated
and gasified. The refrigerant thus gasified is inspired into the compressor 1 through
the heat source device reversing valve 2 and the accumulator 4. In this way, a circulation
cycle is formed to carry out the cooling and heating concurrent operation wherein
heating is principally performed. At this time, the difference between the evaporation
pressure in the indoor heat exchanger 5 of the cooling indoor unit D and that of the
outdoor heat exchanger 3 lessens because of switching to the first main pipe 6 having
such a greater diameter. At that time, the three port switching valves 8 which are
connected to the heating indoor units B and C have the second ports 8b closed, and
the first and third ports 8a and 8c opened. The three port switching valve 8 which
is connected to the cooling indoor unit D has the first port 8a closed, and the second
port 8b and the third port 8c opened.
[0050] In this mode, the first main pipe 6 is at low pressure in it, and the second main
pipe 7 is at high pressure in it, which necessarily causes the fifth check valve 34
and the sixth check valve 35 to conduct for the refrigerant. At this circulation cycle,
the remaining part of the liquefied refrigerant goes into the bypass pipe 14 from
the confluent portion of the second branch joint 11 where the second branch pipes
7b, 7c and 7d join together. The refrigerant which has gone into the bypass pipe 14
is depressurized to low pressure by the third flow controller 15. The refrigerant
thus depressurized carries out heat exchange with the refrigerant in the second branch
pipes 7b, 7c and 7d at the third heat exchanging portions 16b, 16c and 16d, with the
refrigerant in the confluent portion of the second branch pipes 7b, 7c and 7d in the
second branch joint 11 at the second heat exchanging portion 16a, and at the first
heat exchanging portion 19 with the pipe on the refrigerant inlet side of the second
flow controller 13. The refrigerant is evaporated by such heat exchange, and enters
the first main pipe 6. After that, the refrigerant flows into the sixth check valve
35 and then into the outdoor heat exchanger 3 where it performs heat exchange to be
evaporated and gasified. The refrigerant thus gasified is inspired into the compressor
1 through the first four way reversing valve 2 and the accumulator 4.
[0051] On the other hand, the refrigerant in the second branch joint 11 which has carried
out heat exchange and cooled at the first heat exchanging portion 19, the second heat
exchanging portion 16a, and the third heat exchanging portions 16b, 16c and 16d to
obtain sufficient subcooling flows into the indoor unit D which is expected to cool
the room.
[0052] At that time, the second flow controller 13 is fully closed in a normal state.
[0053] Fourthly, the case wherein cooling is principally performed in cooling and heating
concurrent operation will be described with reference to Figure 4.
[0054] In Figure 4, arrows of solid lines indicate the flow of the refrigerant. The compressor
1 has capacity controlled so that a temperature detected by the low pressure saturation
temperature detector 50 achieves a predetermined value. The refrigerant which has
been discharged from the compressor 1 and been a gas having high temperature under
high pressure flows into the outdoor heat exchanger 3 through the reversing valve
2, and carries out heat exchange with outdoor air in the outdoor heat exchanger 3
to take a gas-liquid two phase state having high temperature under high pressure.
Then the refrigerant passes through the third check valve 32 and the second main pipe
7, and is forwarded to the gas-liquid separator 12 in the junction device E. The refrigerant
is separated into a gaseous refrigerant and a liquid refrigerant there, and the gaseous
refrigerant thus separated flows through the first branch joint 10, and the three
way switching valve 8 and the first branch pipe 6d which are connected to the indoor
unit D, in that order, the indoor unit D being expected to heat the room with the
indoor unit D installed in it. The refrigerant flows into the indoor unit D, and carries
out heat exchange with indoor air to be condensed and liquefied, thereby heating the
room. In addition, the refrigerant passes through the first flow controller 9 connected
to the heating indoor unit D, this first flow controller 9 being almost fully opened
under control based on degree of subcooling at the refrigerant outlet of the indoor
heat exchanger 5 of the heating indoor unit D. The refrigerant is slightly depressurized
by this first flow controller 9, and flows into the second branch joint 11. On the
other hand, the remaining liquid refrigerant enters the second branch joint 11 through
the second flow controller 13 which is controlled based on pressures detected by the
first pressure detector 25 and the second pressure detector 26. Then the refrigerant
joins there with the refrigerant which has passed through the heating indoor unit
D. The refrigerant thus joined passes through the second branch joint 11, and then
the second branch pipes 7b and 7c, respectively, and enters the respective indoor
units B and C. The refrigerant which has flowed into the indoor units B and C is depressurized
to low pressure by the first flow controllers 9 of the indoor units B and C, these
first flow controllers 9 being controlled based on degree of superheat at the refrigerant
outlets of the corresponding indoor heat exchangers 5. Then the refrigerant flows
into the indoor heat exchangers 5, and carries out heat exchange with indoor air to
be evaporated and gasified, thereby cooling the rooms. In addition, the refrigerant
thus gasified passes through the first branch pipes 6b and 6c, the three way switching
valves 8, and the first branch joint 10. Then the refrigerant is inspired into compressor
1 through the first main pipe 6, the fourth check valve 33, the four way reversing
valve 2 in the heat source device A, and the accumulator 4. In this way, a circulation
cycle is formed to carry out the cooling and heating concurrent operation wherein
cooling is principally performed. In this mode, the three way switching valves 8 which
are connected to the indoor units B and C have the first ports 8a closed, and the
second and third ports 8b and 8c opened. The three way switching valve 8 which is
connected to the indoor unit D has the second port 8b closed, and the first and third
ports 8a and 8c opened.
[0055] At that time, the first main pipe 6 is at low pressure in it, and the second main
pipe 7 is a high pressure in it, which necessarily causes the third check valve 32
and the fourth check valve 33 to conduct for the refrigerant.
[0056] In this circulation cycle, the liquid refrigerant partly enters the bypass pipe 14
from the confluent portion of the second branch joint 11 where the second branch pipes
7b, 7c and 7d join together. The liquid refrigerant which has entered into the bypass
pipe 14 is depressurized to low pressure by the third flow controller 15. The refrigerant
thus depressurized carried out heat exchange with the refrigerant in the second branch
pipes 7b, 7c and 7d at the third heat exchanging portions 16b, 16c and 16d, and at
the second heat exchanging portion 16a with the refrigerant in the confluent portion
of the second branch pipes 7b, 7c and 7d in the second branch joint 11, and at the
first heat exchanging portion 19 with the refrigerant which flows into the second
flow controller 13. The refrigerant is evaporated by such heat exchange, and enters
the first main pipe 6. The refrigerant which has entered the first main pipe 6 is
inspired into the compressor 1 through the fourth check valve 33, the four way reversing
valve 2 in the heat source device A, and the accumulator 4.
[0057] On the other hand, the refrigerant in the second branch joint 11 which has carried
out heat exchange and cooled at the first heat exchanging portion 19, the second heat
exchanging portion 16a, and the third heat exchanging portions 16b, 16c and 16d to
obtain sufficient subcool flows into the indoor units B and C which are expected to
carry out cooling.
[0058] Now, the oil recovery according to the first embodiment wherein the second flow controller
13 is normally fully closed in only heating, or in cooling and heating concurrent
operation with heating principally performed will be explained, referring to Figures
5-7. Figure 5 is a block diagram showing the oil recovery according to the first embodiment,
Figure 6 is a flowchart showing the oil recovery according to the first embodiment,
and the Figure 7 is a graph showing a change in the valve setting (opening degree)
of the second flow controller 13.
[0059] In Figure 5, reference numeral 61 designates a first timer which measures the duration
that has elapsed since a previous valve setting control was made, for periodically
carrying out a valve setting control of the second flow controller 13 at a first cycle.
The first timer is cleared whenever the compressor 1 starts working or a valve setting
control of the second flow controller 13 is made. Reference numeral 62 designates
a second timer which measures an operating duration of the compressor 1, and which
is cleared whenever the compressor 1 starts working or a second cycle, which is longer
than the first cycle, has elapsed. Reference numeral 63 designates determination means
for incrementally narrowing the valve setting (opening degree) of the second flow
controller by a predetermined value (amount) based on outputs from the first timer
1, and for returning the valve setting of the second flow controller to its initial
setting based on an output from the second timer.
[0060] A control flow for the oil recovery will be explained, referring to Figures 6 and
7.
[0061] At Step 71, the second timer 62 determines whether a predetermined second duration
as the second cycle, or longer, has elapsed or not. If affirmative, the program proceeds
to Step 76. If negative, the program proceeds to Step 72.
[0062] At Step 76, the valve setting of the second flow controller 13 is increased by a
predetermined value (amount), to be returned to its initial value as indicated by
the point
a in Figure 7. At the next Step 77, the time data in the second timer 62 is cleared,
and the program returns to Step 71.
[0063] At Step 72, the first timer 61 determines whether a predetermined first duration
as the first cycle, or longer, has elapsed or not. The first duration is shorter than
the second duration. If affirmative, the program proceeds to Step 73. If negative,
the program returns to Step 71.
[0064] At Step 73, it is determined whether the second flow controller 13 is fully closed
or not. If affirmative, the program proceeds to Step 75. If negative, the program
proceeds to Step 74.
[0065] At Step 74, the valve setting of the second flow controller 13 is narrowed by the
predetermined value (amount), which is less than the predetermined value at Step 76,
as indicated by the point
b in Figure 7. Then, the program proceeds to Step 75.
[0066] At Step 75, the time data in the first timer 61 is cleared, and the program returns
to Step 71.
[0067] In accordance with the first embodiment, the lubricating oil which has flowed from
the second main pipe during operation of the compressor, and stayed at the inlet side
of the second flow controller because of narrow valve setting of the second flow controller
can be returned from the third flow controller or the cooling indoor unit through
the first main pipe by regularly enlarging the valve setting of the second flow controller.
[0068] In the case of only heating, or cooling and heating concurrent operation with heating
principally performed, a control wherein the minimum valve setting is determined and
the second flow controller 13 is always slightly opened to be prevent from being fully
closed can be adopted to prevent the lubricating oil of the compressor from staying
at the inlet side of the second flow controller 13. Such a control is also effective.
In accordance with this control, the lubricating oil of the compressor can be returned
from the third flow controller or the cooling indoor unit to the compressor through
the first main pipe. Although this control involves a minor problem in that heating
capacity slightly deteriorates in a steady manner because the refrigerant always flows
through the second flow controller, the lubricating oil can be prevented from staying
in the junction device, thereby avoiding seizure of the compressor.
EMBODIMENT 2:
[0069] As shown in Figure 8, a capillary tube 51 can be provided in parallel with the second
flow controller 13 to obtain an advantage similar to the provision of the minimum
valve setting in the second flow controller 13.
[0070] The provision of the capillary tube in parallel with the second flow controller can
ensure the passage of the lubricating oil for the compressor during operation of the
compressor even if the second flow controller is fully closed. As a result, the lubricating
oil can be prevented from staying at the inlet side of the second flow controller,
and the lubricating oil can be returned from the third flow controller or the cooling
indoor unit through the first main pipe.
MODIFICATION OF EMBODIMENTS 1-2:
[0071] Although in the above-described embodiments the three way switching valves 8 can
be arranged to selectively connect the first branch pipes 6b, 6c and 6d to either
the first main pipe 6 or the second main pipe 7, spared on off valves such as electromagnetic
on off valves 30 and 31 as shown in Figure 9 can be provided instead of the three
way switching valves to make selective switching, offering similar advantages.
1. An air conditioning apparatus comprising:
a single heat source device (A) including a compressor (1), a reversing valve (2),
an outdoor heat exchanger (3) and an accumulator (4);
a plurality of indoor units (B,C,D) including indoor heat exchangers (5) and first
flow controllers (9);
a first main pipe (6) and a second main pipe (7) connected between the heat source
device (A) and the indoor units (B, C, D);
a first branch joint (10) which can selectively connect one end of the indoor heat
exchanger (5) of each indoor unit (B,C,D) to either the first main pipe (6) or the
second main pipe (7);
a second branch joint (11) which is connected to the other end of the indoor heat
exchanger (5) of each indoor unit (B,C,D) through the first flow controllers (9),
and which connects the other end to the second main pipe (7) through a second flow
controller (13);
the first branch joint (10) and the second branch joint (11) being connected together
through the second flow controller (13), and the second branch joint (11) being connected
to the first main pipe (6) through a third flow controller (15);
a junction device (E) which includes the first branch joint (10), the second flow
controller (13), the third flow controller (15) and the second branch joint (11),
and which is interposed between the heat source device (A) and the indoor units (B,C,D);
the first main pipe (6) having a greater diameter than the second main pipe (7); and
a switching arrangement (40) arranged between the first main pipe (6) and the second
main pipe (7) in the heat source device (A) and operative to connect the first main
pipe (6) and the second main pipe (7) to the low pressure side and the high pressure
side, respectively, of the heat source device (A), when the outdoor heat exchanger
(3) works as a condenser or when it works as an evaporator; characterized in that
it comprises:
a first timer (61) for periodically decreasing the opening degree of the second flow
controller (13) at a first cycle during operation of the compressor (1);
a second timer (62) for periodically returning the second flow controller (13) to
its initial opening degree at a second cycle longer than the first cycle; and
means (63) for decreasing the opening degree of the second flow controller (13) by
a predetermined amount incrementally, based on outputs from the first timer (61),
and for returning the second flow controller (13) to the initial opening degree, based
on an output from the second timer (62).
2. An air conditioning apparatus comprising:
a single heat source device (A) including a compressor (1), a reversing valve (2),
an outdoor heat exchanger (3) and an accumulator (4);
a plurality of indoor units (B,C,D) including indoor heat exchangers (5) and first
flow controllers (9);
a first main pipe (6) and a second main pipe (7) connected between the heat source
device (A) and the indoor units (B, C, D);
a first branch joint (10) which can selectively connect one end of the indoor heat
exchanger (5) of each indoor unit (B,C,D) to either the first main pipe (6) or the
second main pipe (7);
a second branch joint (11) which is connected to the other end of the indoor heat
exchanger (5) of each indoor unit (B,C,D) through the first flow controllers (9),
and which connects the other end to the second main pipe (7) through a second flow
controller (13);
the first branch joint (10) and the second branch joint (11) being connected together
through the second flow controller (13), and the second branch joint (11) being connected
to the first main pipe (6) through a third flow controller (15);
a junction device (E) which includes the first branch joint (10), the second flow
controller (13), the third flow controller (15) and the second branch joint (11),
and which is interposed between the heat source device (A) and the indoor units (B,C,D);
the first main pipe (6) having a greater diameter than the second main pipe (7); and
a switching arrangement (40) arranged between the first main pipe (6) and the second
main pipe (7) in the heat source device (A) and operative to connect the first main
pipe (6) and the second main pipe (7) to the low pressure side and the high pressure
side, respectively, of the heat source device (A), when the outdoor heat exchanger
(3) works as a condenser or when it works as an evaporator; characterized in that
a predetermined minimum value is set with respect to the opening degree of the second
flow controller (13) so as to prevent it from being fully closed during operation
of the compressor (1).
3. An air conditioning apparatus comprising:
a single heat source device (A) including a compressor (1), a reversing valve (2),
an outdoor heat exchanger (3) and an accumulator (4);
a plurality of indoor units (B,C,D) including indoor heat exchangers (5) and first
flow controllers (9);
a first main pipe (6) and a second main pipe (7) connected between the heat source
device (A) and the indoor units (B,C,D);
a first branch joint (10) which can selectively connect one end of the indoor heat
exchanger (5) of each indoor unit (B,C,D) to either the first main pipe (6) or the
second main pipe (7);
a second branch joint (11) which is connected to the other end of the indoor heat
exchanger (5) of each indoor unit (B,C,D) through the first flow controllers (9),
and which connects the other end to the second main pipe (7) through a second flow
controller (13);
the first branch joint (10) and the second branch joint (11) being connected together
through the second flow controller (13), and the second branch joint (11) being connected
to the first main pipe (6) through a third flow controller (15);
a junction device (E) which includes the first branch joint (10), the second flow
controller (13), the third flow controller (15) and the second branch joint (11),
and which is interposed between the heat source device (A) and the indoor units (B,C,D);
the first main pipe (6) having a greater diameter than the second main pipe (7); and
a switching arrangement (40) arranged between the first main pipe (6) and the second
main pipe (7) in the heat source device (A) and operative to connect the first main
pipe (6) and the second main pipe (7) to the low pressure side and the high pressure
side, respectively, of the heat source device (A), when the outdoor heat exchanger
(3) works as a condenser or when it works as an evaporator; characterized in that
a capillary (51) is arranged in parallel with the second flow controller (13).
1. Klimaanlage, die folgendes aufweist:
- eine einzige Wärmequelle (A), die einen Kompressor (1), ein Umschaltventil (2),
einen Wärmetauscher (3) im Freien und einen Speicher (4) aufweist;
- eine Vielzahl von Innenraumeinheiten (B, C, D) mit Innenraumwärmetauschern (5) und
ersten Durchflußreglern (9);
- eine erste Hauptleitung (6) und eine zweite Hauptleitung (7), die zwischen die Wärmequelle
(A) und die Innenraumeinheiten (B, C, D) geschaltet sind;
- eine erste Abzweigverbindung (10), die selektiv das eine Ende des Innenraumwärmetauschers
(5) von jeder Innenraumeinheit (B, C, D) entweder mit der ersten Hauptleitung (6)
oder der zweiten Hauptleitung (7) verbinden kann;
- eine zweite Abzweigverbindung (11), die mit dem anderen Ende des Innenraumwärmetauschers
(5) von jeder Innenraumeinheit (B, C, D) über die ersten Durchflußregler (9) verbunden
ist und die das andere Ende über einen zweiten Durchflußregler (13) mit der zweiten
Hauptleitung (7) verbindet;
- wobei die erste Abzweigverbindung (10) und die zweite Abzweigverbindung (11) über
den zweiten Durchflußregler (13) miteinander verbunden sind und wobei die zweite Abzweigverbindung
(11) über einen dritten Durchflußregler (15) mit der ersten Hauptleitung (6) verbunden
ist;
- eine Verbindungseinheit (E), welche die erste Abzweigverbindung (10), den zweiten
Durchflußregler (13), den dritten Durchflußregler (15) und die zweite Abzweigverbindung
(11) aufweist und die zwischen die Wärmequelle (A) und die Innenraumeinheiten (B,
C, D) geschaltet ist;
- wobei die erste Hauptleitung (6) einen größeren Durchmesser besitzt als die zweite
Hauptleitung (7); und
- eine Schaltanordnung (40), die zwischen der ersten Hauptleitung (6) und der zweiten
Hauptleitung (7) in der Wärmequelle (A) angeordnet ist und in der Weise arbeitet,
daß sie die erste Hauptleitung (6) und die zweite Hauptleitung (7) mit der Niederdruckseite
bzw. der Hochdruckseite der Wärmequelle (A) verbindet, wenn der Wärmetauscher (3)
im Freien als Kondensator arbeitet oder als Verdampfer arbeitet,
dadurch gekennzeichnet,
daß die Klimaanlage folgendes aufweist:
- eine erste Zeitsteuerung (61), um den Öffnungsgrad des zweiten Durchflußreglers
(13) in einem ersten Zyklus während des Betriebes des Kompressors (1) periodisch zu
verringern;
- eine zweite Zeitsteuerung (62), um den zweiten Durchflußregler (13) in einem zweiten
Zyklus, der länger ist als der erste Zyklus, periodisch auf seinen Öffnungsgrad zu
Beginn zurückzustellen; und
- eine Einrichtung, um auf der Basis von Ausgangssignalen von der ersten Zeitsteuerung
(61) den öffnungsgrad des zweiten Durchflußreglers (13) inkrementmäßig um einen vorgegebenen
Wert zu verringern, und um auf der Basis eines Ausgangssignals von der zweiten Zeitsteuerung
(62) den zweiten Durchflußregler (13) auf den öffnungsgrad zu Beginn zurückzustellen.
2. Klimaanlage, die folgendes aufweist:
- eine einzige Wärmequelle (A), die einen Kompressor (1), ein Umschaltventil (2),
einen Wärmetauscher (3) im Freien und einen Speicher (4) aufweist;
- eine Vielzahl von Innenraumeinheiten (B, C, D) mit Innenraumwärmetauschern (5) und
ersten Durchflußreglern (9);
- eine erste Hauptleitung (6) und eine zweite Hauptleitung (7), die zwischen die Wärmequelle
(A) und die Innenraumeinheiten (B, C, D) geschaltet sind;
- eine erste Abzweigverbindung (10), die selektiv das eine Ende des Innenraumwärmetauschers
(5) von jeder Innenraumeinheit (B, C, D) entweder mit der ersten Hauptleitung (6)
oder der zweiten Hauptleitung (7) verbinden kann;
- eine zweite Abzweigverbindung (11), die mit dem anderen Ende des Innenraumwärmetauschers
(5) von jeder Innenraumeinheit (B, C, D) über die ersten Durchflußregler (9) verbunden
ist und die das andere Ende über einen zweiten Durchflußregler (13) mit der zweiten
Hauptleitung (7) verbindet;
- wobei die erste Abzweigverbindung (10) und die zweite Abzweigverbindung (11) über
den zweiten Durchflußregler (13) miteinander verbunden sind und wobei die zweite Abzweigverbindung
(11) über einen dritten Durchflußregler (15) mit der ersten Hauptleitung (6) verbunden
ist;
- eine Verbindungseinheit (E), welche die erste Abzweigverbindung (10), den zweiten
Durchflußregler (13), den dritten Durchflußregler (15) und die zweite Abzweigverbindung
(11) aufweist und die zwischen die Wärmequelle (A) und die Innenraumeinheiten (B,
C, D) geschaltet ist;
- wobei die erste Hauptleitung (6) einen größeren Durchmesser besitzt als die zweite
Hauptleitung (7); und
- eine Schaltanordnung (40), die zwischen der ersten Hauptleitung (6) und der zweiten
Hauptleitung (7) in der Wärmequelle (A) angeordnet ist und in der Weise arbeitet,
daß sie die erste Hauptleitung (6) und die zweite Hauptleitung (7) mit der Niederdruckseite
bzw. der Hochdruckseite der Wärmequelle (A) verbindet, wenn der Wärmetauscher (3)
im Freien als Kondensator arbeitet oder als Verdampfer arbeitet,
dadurch gekennzeichnet,
daß ein vorgegebener Minimalwert im Hinblick auf den
Öffnungsgrad des zweiten Durchflußreglers (13) vorgegeben ist, um zu verhindern, daß
er während des Betriebes des Kompressors (1) vollständig geschlossen wird.
3. Klimaanlage, die folgendes aufweist:
- eine einzige Wärmequelle (A), die einen Kompressor (1), ein Umschaltventil (2),
einen Wärmetauscher (3) im Freien und einen Speicher (4) aufweist;
- eine Vielzahl von Innenraumeinheiten (B, C, D) mit Innenraumwärmetauschern (5) und
ersten Durchflußreglern (9);
- eine erste Hauptleitung (6) und eine zweite Hauptleitung (7), die zwischen die Wärmequelle
(A) und die Innenraumeinheiten (B, C, D) geschaltet sind;
- eine erste Abzweigverbindung (10), die selektiv das eine Ende des Innenraumwärmetauschers
(5) von jeder Innenraumeinheit (B, C, D) entweder mit der ersten Hauptleitung (6)
oder der zweiten Hauptleitung (7) verbinden kann;
- eine zweite Abzweigverbindung (11), die mit dem anderen Ende des Innenraumwärmetauschers
(5) von jeder Innenraumeinheit (B, C, D) über die ersten Durchflußregler (9) verbunden
ist und die das andere Ende über einen zweiten Durchflußregler (13) mit der zweiten
Hauptleitung (7) verbindet;
- wobei die erste Abzweigverbindung (10) und die zweite Abzweigverbindung (11) über
den zweiten Durchflußregler (13) miteinander verbunden sind und wobei die zweite Abzweigverbindung
(11) über einen dritten Durchflußregler (15) mit der ersten Hauptleitung (6) verbunden
ist;
- eine Verbindungseinheit (E), welche die erste Abzweigverbindung (10), den zweiten
Durchflußregler (13), den dritten Durchflußregler (15) und die zweite Abzweigverbindung
(11) aufweist und die zwischen die Wärmequelle (A) und die Innenraumeinheiten (B,
C, D) geschaltet ist;
- wobei die erste Hauptleitung (6) einen größeren Durchmesser besitzt als die zweite
Hauptleitung (7); und
- eine Schaltanordnung (40), die zwischen der ersten Hauptleitung (6) und der zweiten
Hauptleitung (7) in der Wärmequelle (A) angeordnet ist und in der Weise arbeitet,
daß sie die erste Hauptleitung (6) und die zweite Hauptleitung (7) mit der Niederdruckseite
bzw. der Hochdruckseite der Wärmequelle (A) verbindet, wenn der Wärmetauscher (3)
im Freien als Kondensator arbeitet oder als Verdampfer arbeitet,
dadurch gekennzeichnet,
daß eine Kapillarröhre (51) parallel zu dem zweiten Durchflußregler (13) angeordnet
ist.
1. Appareil de conditionnement d'air comprenant : un dispositif unique formant source
de chaleur (A) incluant un compresseur (1), une vanne d'inversion (2), un échangeur
de chaleur extérieur (3) et un accumulateur (4) ;
une pluralité d'unités intérieures (B,C,D) incluant des échangeurs de chaleur intérieurs
(5) et des premiers dispositifs de commande d'écoulement (9) ;
un premier tuyau principal (6) et un deuxième tuyau principal (7) connecté entre le
dispositif formant source de chaleur (A) et les unités intérieures (B,C,D) ;
un premier raccord de branchement (10) qui permet de relier sélectivement une extrémité
de l'échangeur de chaleur intérieur (5) de chaque unité intérieure (B,C,D) soit au
premier tuyau principal (6) soit au deuxième tuyau principal (7) ;
un deuxième raccord de branchement (11) qui est relié à l'autre extrémité de l'échangeur
de chaleur intérieur (5) de chaque unité intérieure (B,C,D) par les premier dispositifs
de commande d'écoulement (9) et qui relie l'autre extrémité au deuxième tuyau principal
(7) par un deuxième dispositif de commande d'écoulement (13) ;
le premier raccord de branchement (10) et le deuxième raccord de branchement (11)
étant reliés ensemble par le deuxième dispositif de commande d'écoulement (13), et
le deuxième raccord de branchement (11) étant relié au premier tuyau principal (6)
par un troisième dispositif de commande d'écoulement (15) ;
un dispositif de jonction (E) qui inclut le premier raccord de branchement (10), le
deuxième dispositif de commande d'écoulement (13), le troisième dispositif de commande
d'écoulement (15) et le deuxième raccord de branchement (11), et qui est interposé
entre le dispositif formant source de chaleur (A) et les unités intérieures (B,C,D)
;
le premier tuyau principal (6) ayant un plus grand diamètre que le deuxième tuyau
principal (7) ; et
un agencement de commutation (40) agencé entre le premier tuyau principal (6) et le
deuxième tuyau principal (7) dans le dispositif formant source de chaleur (A) et fonctionnant
pour relier le premier tuyau principal (6) et le deuxième tuyau principal (7) au côté
basse pression et au côté haute pression, respectivement, du dispositif formant source
de chaleur (A) lorsque l'échangeur de chaleur extérieur (3) fonctionne comme condensateur
ou lorsqu'il fonctionne comme évaporateur ; caractérisé en ce qu'il comporte :
une première horloge (61) pour diminuer périodiquement le degré d'ouverture du deuxième
dispositif de commande d'écoulement (13) à un premier cycle pendant le fonctionnement
du compresseur (1) ;
une deuxième horloge (62) pour ramener périodiquement le deuxième dispositif de commande
d'écoulement (13) à son degré d'ouverture initial à un deuxième cycle qui est plus
long que le premier cycle ; et
un moyen (63) pour diminuer le degré d'ouverture du deuxième dispositif de commande
d'écoulement (13) suivant une valeur prédéterminée par incréments, sur la base des
sorties de la première horloge (61), et pour ramener le deuxième dispositif de commande
d'écoulement (13) à un degré d'ouverture initial, basé sur une sortie de la deuxième
horloge (62).
2. Appareil de conditionnement d'air comprenant : un dispositif unique formant source
de chaleur (A) incluant un compresseur (1), une vanne d'inversion (2), un échangeur
de chaleur extérieur (3) et un accumulateur (4) ;
plusieurs unités intérieures (B,C,D) incluant des échangeurs de chaleur intérieurs
(5) et des premiers dispositifs de commande d'écoulement (9) ;
un premier tuyau principal (6) et un deuxième tuyau principal (7) connectés entre
le dispositif formant source de chaleur (A) et les unités intérieures (B,C,D) ;
un premier raccord de branchement (10) qui peut sélectivement relier une extrémité
de l'échangeur de chaleur intérieur (5) de chaque unité intérieure (B,C,D) soit au
premier tuyau principal (6) soit au deuxième tuyau principal (7) ;
un deuxième raccord de branchement (11) qui est relié à l'autre extrémité de l'échangeur
de chaleur intérieur (5) de chaque unité intérieure (B,C,D) par les premiers dispositifs
de commande d'écoulement (9) et qui relie l'autre extrémité au deuxième tuyau principal
(7) par un deuxième dispositif de commande d'écoulement (13) ;
le premier raccord de branchement (10) et le deuxième raccord de branchement (11)
étant reliés ensemble par le deuxième dispositif de commande d'écoulement (13), et
le deuxième raccord de branchement (11) est relié au premier tuyau principal (6) par
un troisième dispositif de commande d'écoulement (15) ;
un dispositif de jonction (E) qui comporte le premier raccord de branchement (10),
le deuxième dispositif de commande d'écoulement (13), le troisième dispositif de commande
d'écoulement (15) et le deuxième raccord de branchement (11) et qui est interposé
entre le dispositif formant source de chaleur (A) et les unités intérieures (B,C,D)
;
le premier tuyau principal (6) ayant un plus grand diamètre que le deuxième tuyau
principal (7) ; et
un agencement de commutation (40) agencé entre le premier tuyau principal (6) et le
deuxième tuyau principal (7) dans le dispositif formant source de chaleur (A) et fonctionnant
pour relier le premier tuyau principal (6) et le deuxième tuyau principal (7) au côté
basse pression et au côté haute pression, respectivement, du dispositif formant source
de chaleur (A) lorsque l'échangeur de chaleur extérieur (3) fonctionne comme condensateur
ou bien lorsqu'il fonctionne comme évaporateur ; caractérisé en ce qu'une valeur minimale
prédéterminée est établie relativement au degré d'ouverture du deuxième dispositif
de commande d'écoulement (13) pour empêcher qu'il soit entièrement fermé pendant le
fonctionnement du compresseur (1).
3. Appareil de conditionnement d'air comprenant :
un dispositif unique formant source de chaleur (A) incluant un compresseur (1), une
vanne d'inversion (2), un échangeur de chaleur extérieur (3) et un accumulateur (4)
;
une pluralité d'unités intérieures (B,C,D) incluant des échangeurs de chaleur intérieurs
(5) et des premiers dispositifs de commande d'écoulement (9) ;
un premier tuyau principal (6) et un deuxième tuyau principal (7) connectés entre
le dispositif formant source de chaleur (A) et les unités intérieures (B,C,D) ;
un premier raccord de branchement (10) qui peut sélectivement connecter une extrémité
de l'échangeur de chaleur intérieur (5) de chaque unité intérieure (B,C,D) soit au
premier tuyau principal (6) soit au deuxième tuyau principal (7) ;
un deuxième raccord de branchement (11) qui est relié à l'autre extrémité de l'échangeur
de chaleur intérieur (5) de chaque unité intérieure (B,C,D) par les premiers dispositifs
de commande d'écoulement (9) et qui relie l'autre extrémité au deuxième tuyau principal
(7) par un deuxième dispositif de commande d'écoulement (13) ;
le premier raccord de branchement (10) et le deuxième raccord de branchement (11)
étant reliés ensemble par le deuxième dispositif de commande d'écoulement (13), et
le deuxième raccord de branchement (11) étant relié au premier tuyau principal (6)
par un troisième dispositif de commande d'écoulement (15) ;
un dispositif de jonction (E) qui inclut le premier raccord de branchement (10), le
deuxième dispositif de commande d'écoulement (13), le troisième dispositif de commande
d'écoulement (15) et le deuxième raccord de branchement (11) et qui est interposé
entre le dispositif formant source de chaleur (A) et les unités intérieures (B,C,D)
;
le premier tuyau principal (6) ayant un plus grand diamètre que le deuxième tuyau
principal (7) ; et
un agencement de commutation (40) agencé entre le premier tuyau principal (6) et le
deuxième tuyau principal (7) dans le dispositif formant source de chaleur (A) et fonctionnant
pour relier le premier tuyau principal (6) et le deuxième tuyau principal (7) au côté
basse pression et au côté haute pression, respectivement, du dispositif formant source
de chaleur (A) lorsque l'échangeur de chaleur extérieur (3) fonctionne comme condensateur
ou lorsqu'il fonctionne comme évaporateur ; caractérisé en ce qu'un capillaire (51)
est agencé parallèlement au deuxième dispositif de commande d'écoulement (13).